Parent support has been identified as one of the most important protective factors for adolescent substance use as well as an important predictor for favorable treatment outcomes for adolescents diagnosed with substance use disorder (SUD). Nevertheless, many parents are not fully aware of the substance use problem of their children, nor do they have the information and support they need in order to effectively assist or work with their children addressing substance abuse problems. We propose to develop a social media intervention Parents United with Responsive Parents for Online Support and Education (PURPOSE) to empower parents of adolescents in treatment for SUD so that they can effectively support their child's recovery. PURPOSE takes advantage of the now commonly used social media platform (Facebook) to provide a safe and flexible space where parents share, learn, and receive support from other responsive parents facing similar problems. Grounded in cognitive behavioral theories of behavior change, PURPOSE will use peer-led online groups to promote parental support and involvement in adolescent recovery. Thus, the proposed study has the following aims: (1) to develop PURPOSE, a social-media based intervention that provides information and coping tools for parents/guardians of adolescent children with a SUD; (2) to determine the feasibility and acceptability of PURPOSE that uses online peer-led intervention delivery; and (3) to conduct a pilot control trial to provide preliminry data on this intervention so as to determine if social media-based parent support group involvement positively impacts parent outcomes (reduced stigma and distress, improved parent monitoring, and increased engagement in adolescent treatment) and adolescent outcomes (treatment retention and abstinence). Results will expand the scientific literature on the role of parental support in adolescent recovery as well as respond to NIDA's call for increased understanding of the feasibility and utility of social media to enhance traditional treatment and self-help groups. These pilot efforts will also provide the groundwork for a formal trial investigating the short- and long-term impact of online social networking on lasting cognitive, emotional, and behavioral change in SUD adolescents and their parents.